Ice tray



Feb. 11, 1947. c, SYNYNESTVEDT 2,415,451 I ICE TRAY Filed Nov. 11, 1943 2 Sheets-Sheet l F/gZ 4? 4 4 1947- c. H. SYNNESTVEDT 2. 15.45

ICE TRAY Filed Nov, 11, 1943 2 Sheets-Sheet 2 Patented Feb. 11, 1947 U-NlTED- sures \PA'ITENT orrlclz ICE may Carl H. Synnestvedt, Bryn Athyn, Pa., assignor to Philco Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application November 11, 1943, Serial No. 509,8{38 Claims; (01. 62-1085) The present invention relates generally to domestic refrigeration and pertains more particularly to ice trays adapted for use in the fast freezing compartment of a household mechanical refrigerator.

' It'is one of the more important objects of the invention to provide a tray capable of forming individual ice masses, which is constructed and arranged so that the ice masses, when formed,

are automatically loosened and lifted outwardly of the tray to be readily grasped and removed by hand, as and when needed.

An equally important object of the present invention resides in the provision of a tray adapted to form ice masses or cubes, which is characterized by its simplicity of construction and which can be manufactured at relatively low cost, and used ina conventional evaporator included in the refrigerating-system of household mechanical refrigerators without requiring special installations therein. r

It is also among the more important objects of the invention to provide a tray of the character. set forth having means defining a. mold to receive a quantity of waterto be frozen into ice, said mold and tray cooperating to form a space therebetween, which space is filled with a solution having a, freezing point lower than that of water,

so-that the expansion forces of such a solution may be utilized to break the bond between the mold and water ice frozen therein, the structure and association of the tray and mold being such that the whole of said.expansion forces are controlled for full and direct action on the mold to insure automatic loosening and lifting of the ice from the latter.

A further object of the invention resides in the provision of an ice tray of the general type mentioned which incorporates means facilitating ready and accurate filling of the separate cups or molds to a predetermined substantially uniform level throughout the entire tray, so that raising 'of thefrozen cubes predisposes the same in a position for ready access and removal.

.Other objects and advantages of theinvention will become apparent to those skilled in the art from the following description based upon the accompanying drawings, in which:

. Figure '1 is a perspective view illustrating one form of the invention;

Figure 2 is an enlarged transverse section taken I on line'2-2, Figure 1;

Figure 3 is a, cross-sectional detail on an enlarged. scale, lookingin the general direction indicated by arrow 8-4,'Figure 1;

Figure 4 is a vertical section looking in the gen eral direction of arrows 4-4, Figure 1 Figure 5 is a perspective illustration of a portion of the frame work included in the structure of the ice cube molding member;

Figure 6 is a somewhat diagrammatic representation of the action of the expansion forces in freeing and lifting an ice cube in that form of the invention shown in Figures 1 and 2;

Figure 7 is a top plan of a portion of an ice cube tray constructed in accordance with another form of the invention;

Figure 8 i a, longitudinal section taken on line I preferably-metal, and is given a generally rectangular shallow configuration. The ice cube mold member 42 is preferably made of pliable material such as rubber, plastic or'the like, and, asshown, may be molded in one piece and shaped to form a plurality of water receiving and retaining cups. l3 of generally frustro-conical shape.

In accordance with the invention, the marginal edges of the ice cube mold member defining the cups i3, are to be maintained in'fixed position with respect to the tray member H and for that purpose, a-wire frame it provided with cross pieces i5 and it may be embedded in beads ii at said marginal edges of the mold, thereby imparting rigidity thereto. 'The longitudinal and side edg'es of the mold member it are preferably secured to the corresponding edges of the tray member II and this may conveniently be accomplished by forming the tray member with a generally L-shaped flange l8 providing a seat as shown at IQ for the bead I I surrounding the mold member, said flange then being pressed down or rolled over said head in the manner more clearly shown in Figure 1 of the drawings.

When assembled, the tray member H and mold member I: cooperate to define a space 20 between adjacent walls thereof and also between the adjacent outer walls of the cups i3, said s a e 20 being filled with a solution having the properties to be, fully described hereinafter In order to been completely filled.

In practice, it is desirable that eaoh'water receiving and retaining cup i3 be filled'to a substantially uniform level, and itis preferable that this level be determined with respect to the upper edge portions of the tray and mold members. As a convenient means to attain these ends, each division defining the individual cups i3 is provided with a passageway 22 which establishes communication between adjacent cups so that the water within the mold member will surfaces surrounding the same so that normally, the removal of the ice cubes is somewhat dimcult. However, in accordance with the present invention, these difllcu'ltles are effectively overcome since the bond between the ice cubes C and their molding cups i3 is automatically broken and the ice cubes are lifted in relation to the tray during the freezing process of the solution which takes place subsequently to the freezing of the water within said cups into ice cubes;

seek a uniform level in each cup by flowing from one cup to another through the passageways, the depth of said passageways being such as to form visual markings indicative of the level to which the mold member as a whole, is to be filled. Moreover, the marginal edge of eachcup I! may be formed with sharply slanting surfaces 23 which terminate on a line substantially level with the bottom of the passageways 22 thus providing additional visual means for indicating the desired water level. The formation and location ofthe slanting surfaces 23 also facilitate removal of the ice cubes when raised in relation to the tray and mold members in the manner to be fully described hereinafter.

- In order that the passageways 22 may readily be formed in the divisions defining the individual cups IS, the cross-pieces l5 and ii of the wire frame H may be bent to provide substantially U-shaped portions accommodating such passagethin thereby assuring increased conductivity, and

accordingly hastening the freezing of the water within said cup.

In the --form of the invention more clearly illustrated in Figures '7 and 8, the cups iii are formed with a bottom 24a slightly spaced from the bottom surface of the tray member II and having a re-entrant portion 25, that is, a portlon extending upwardly for a distance into the cups [3; This re-entrant portion may be of any suitable desired shape but as shown is preferably dome-shaped.

It is particularly to be noted that, in this latter form of the invention, the space between the bottom surface of thetray member H and the bottom 24a of the mold member l2, as well as the spaces between the adjacent surfaces of the cups l3 and between the surfaces .of said cups and side walls of the tray member are filled with the relatively slow. freezing solution, so that each cup is completely surrounded with said solution.

In using-either type of ice cube molding tray, the cups ii are filled with water to the leveldetermined by the passageways 22 and terminat- In this connection, it will be appreciated that since the water within the cups l3 freezes first and because of the shape of the cups l3 and the particular association of the mold member l2 and tray member II, the expansion resulting from the subsequent freezing of the solution about said cups acts against the latter with a positively directed and controlled lateral force as represented by the arrowsA in Figures 6 and 9, thereby distorting the normal shape of said cups l3 and causing the ice cubes to break away from the latter and rise in relation thereto. whereupon the ice cubes may readily be picked out as and when needed.

In the. form of the invention illustrated in Figures 7 and 9, a part of the expansion forces are also directed against the bottom 24a of each of cups I3, in a substantially vertical direction, as indicated by the arrows B in Figure 9, so that although the freezing of the water within said cups may be, slower than with the form of the invention illustrated, for instance in Figure 2, there is the compensating eflect resulting from the additional lifting action imposed upon the individual ice cubes. y

In accordance with this invention, the control of the expansion forces for full and direct action on the individual ice cube molding cups to insure automatic loosening and lifting of said cubes is assured, due to the rigidity of the upper edge of the mold member and its fixed position Viiiil necessary, this resistance to bowing may be assured by providing the bottom of the tray member with rib-like formations extending lengthwise of said bottoms, for instance as shown.

at 26 in Figures 7 and 9. i

It is to be understood that the invention is not limited to the use of any one specific solution for filling the space between the mold and tray members so long as the solution chosen has a freezing point lower than that of water and possesses at freezing an expansion percentage sufficient to cause the freezing and raising of the ice cube from its mold cup. For example, a mixture of water and salt consisting of approximately 23.6% salt by weight would fill the requirements of such a solution, since it freezes at a rate sufficiently slow to allow the water within the cups to freeze sufficiently solid before the solution freezes so that the ice cubes do not crumble under the expansion force liberated by the freezing solution,

and since such a solution, at freezing, expands approximately 8% it isamply sufficient to free- .and raise the ice cubes from their molding cups.

the scope of the subjoined claims is to be considered within the spirit of the invention.

I claim:

1. An ice making device comprising a. tray member of relatively rigid material, an ice molding member of relatively pliable material mounted in said tray member, said ice molding member having side wall portions. and a bottom portion, said bottom portion of the ice molding member having a reentrant area, said side wall portions and bottom portion with its reentrant' area being disposed with respect to the adjoining surfaces of the tray member to provide .a continuous space between said tray and molding member, and a solution in said space, said solution having a freezing point lower than that of water.

2. In an ice making device, a self-contained open top receptacle comprising outer and inner tray elements, said inner element being joined to the outer element so as to provide a sealed interspace and having a pliable-walled pocket depending in said space, and a freezable medium-adapted to expand upon freezing confined within said space and about said pocket, said freezable medium having a freezing point below that of water and substantially filling said space whereby expansion forces within said body resulting from freezing of the said medium may react through said pliable wall to displace a previously frozen ice mass upwardly in said pocket.

3. In an ice making device, a self-contained open top receptacle comprising outer and inner tray elements, said inner element being. joined to the outer elementso as to provide a sealed inte r space and having a pliable-walled pocket depending in said space, and a freezable' medium adapted to expand upon freezing confined within said space and about said pocket, the walls of said pocket converging downwardly and said ,freezable'medium having a freezing point below that of water and substantially filling said space whereby expansion forces within said body resulting from freezing of the said medium may react through said pliable wall to displace a previously frozen ice mass upwardly in-sald pocket.

4. In an ice making device, a self-contained open top receptacl comprising outer and inner tray elements, said inner element being joined to the outer. element so as to provide a sealed interspace and having a plurality of pliable-walled pockets depending in said space, means for preventing displacement of the upper edge portions of said pockets from the normal planeof the top of said receptacle, and a freezable medium adapted to expand upon freezing confined within said space and about said pockets, said freezable medium having a freezing point below that of water and substantially filling said space whereby expansion forces within the body of freezable medium resulting from freezing of the latter may react through said pliable walls to dis- ,place previously frozen ice masses upwardly in said pockets.

5. In an ice making device, a self-contained open top receptacle comprising outer and inner tray elements, said inner element being joined to the outer element so as to provide a sealed interspace and having a plurality of pliable-walled pockets dependingin said space, means for preventing displacement of the upper edge portions of said pockets from th normal plane of the top of said receptacle, and a freezable medium adapted to expand upon freezing confined within said space and about said pockets, the walls of said pockets converging downwardly and said freezable 'medium having a freezing point below that of water and substantially filling said space .whereby expansion forces within the body of freezable medium resulting from freezing of the latter may react through said pliable walls to dis-.

place previously frozen ice masses upwardly in 2,373,251 Mallard 

